Re: [rules-dev] Scala
by Chun, Byung C
I'm only an observer to this list, although greatly impressed by what you guys have accomplished, outstanding to be honest. Just a quick question though, have you looked at Groovy? Not to get into religious language wars, but you might get the same compactness and literate style with perhaps more fluid integration w Java code.
Jin
Mobile: 857-222-7518
----- Original Message -----
From: rules-dev-bounces(a)lists.jboss.org <rules-dev-bounces(a)lists.jboss.org>
To: Rules Dev List <rules-dev(a)lists.jboss.org>
Sent: Sun Jan 11 19:12:45 2009
Subject: [rules-dev] Scala
Hey All. I have been looking into scala for sometime, and recently
started using it for a testing tool (kind of a replacement for the
"fit for rules" library).
I have been quite impressed with it, the tool integration (with
intelliJ) is outstanding, and it works nice with maven (even with
mixed java source).
Assuming this goes well, I am thinking of extending the usage of scala
to the server side components of bits of guvnor (obviously the client
is still GWT). Probably in a small way at first (I have found that
common annoying bits of code in java can be much clearer in scala -
examples to come !).
I was interested in what people think about this? Does it make it
harder for people to get into the code (I am not aiming to write the
densest scala, just use it when approriate)?
The main downsides I see are: Eclipse support - the plugin for eclipse
for scala is not great at the moment (netbeans or intelliJ would be
better), and general familiarity for people to read (although I
personally think it would take anyone who reads this list minutes to
learn enough to follow the simple things I would do).
Thoughts? Objections?
FAQ: Why scala? well its closer to java in intent then all other
popular JVM languages (ie its static) and compiles down similarly to
result in similar performance (better in some cases). I use "closures"
a lot (thanks to GWT that got be in the habit) but the inner class way
of doing it in java gets combersome.
--
Michael D Neale
home: www.michaelneale.net
blog: michaelneale.blogspot.com
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17 years, 2 months
Re: [rules-dev] Scala
by Michael Rhoden
While not just stay with Java? I don't understand the need to mix another language into codebase, which has little support compared to java. If it's just to make your efforts a little faster, I would argue you loose value in the project by having yet another aspect to the learning curve for every other developer.
Betamax was better than VHS and laser disc was before it's time. Sometimes it pays to follow the masses, when you expect them to use your product ;)
----- Original Message -----
From: "Michael Neale" <michael.neale(a)gmail.com>
To: "Rules Dev List" <rules-dev(a)lists.jboss.org>
Sent: Monday, January 12, 2009 6:41:42 PM GMT -06:00 US/Canada Central
Subject: Re: [rules-dev] Scala
Yeah netbeans is getting pretty decent scala support - improving all the time.
people are using the eclipse one, so it is slowly getting better, its
just that it is unstable that troubles me.
yes, as Mark said, groovy is fine, but its quite a different language
in semantics if not syntax. Whereas scala is probably more a 1 for 1
replacement (although it can have a stepper learning curve in some
areas) and a very fast powerful language (not that for this bit speed
is too sensitive).
Whilst initially there may not be automated refactorings, as it is a
static language (you tend to never require reflection in it) it can
cope with manual refactorings much better then java (as you get
compile errors and warnings for any missed changes).
Initially I am looking at it for a testing module that uses
spreadsheets, so will see how that goes (its fairly isolated).
On Mon, Jan 12, 2009 at 1:02 PM, Edson Tirelli <tirelli(a)post.com> wrote:
>
> I like the functional aspect of scala and the way it promotes some
> modeling good practices. The main worry is really, once we start
> implementing things on it, to maintain that codebase, and for that tooling
> is paramount. So, if maven works well and IntelliJ can do some minimum work
> on refactories, I like the idea of an incremental inclusion of scala
> components where they make sense.
>
> []s
> Edson
>
> 2009/1/11 Michael Neale <michael.neale(a)gmail.com>
>>
>> Hey All. I have been looking into scala for sometime, and recently
>> started using it for a testing tool (kind of a replacement for the
>> "fit for rules" library).
>> I have been quite impressed with it, the tool integration (with
>> intelliJ) is outstanding, and it works nice with maven (even with
>> mixed java source).
>>
>> Assuming this goes well, I am thinking of extending the usage of scala
>> to the server side components of bits of guvnor (obviously the client
>> is still GWT). Probably in a small way at first (I have found that
>> common annoying bits of code in java can be much clearer in scala -
>> examples to come !).
>>
>> I was interested in what people think about this? Does it make it
>> harder for people to get into the code (I am not aiming to write the
>> densest scala, just use it when approriate)?
>>
>> The main downsides I see are: Eclipse support - the plugin for eclipse
>> for scala is not great at the moment (netbeans or intelliJ would be
>> better), and general familiarity for people to read (although I
>> personally think it would take anyone who reads this list minutes to
>> learn enough to follow the simple things I would do).
>>
>> Thoughts? Objections?
>>
>> FAQ: Why scala? well its closer to java in intent then all other
>> popular JVM languages (ie its static) and compiles down similarly to
>> result in similar performance (better in some cases). I use "closures"
>> a lot (thanks to GWT that got be in the habit) but the inner class way
>> of doing it in java gets combersome.
>>
>> --
>> Michael D Neale
>> home: www.michaelneale.net
>> blog: michaelneale.blogspot.com
>> _______________________________________________
>> rules-dev mailing list
>> rules-dev(a)lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-dev
>
>
>
> --
> Edson Tirelli
> JBoss Drools Core Development
> JBoss, a division of Red Hat @ www.jboss.com
>
> _______________________________________________
> rules-dev mailing list
> rules-dev(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-dev
>
>
--
Michael D Neale
home: www.michaelneale.net
blog: michaelneale.blogspot.com
_______________________________________________
rules-dev mailing list
rules-dev(a)lists.jboss.org
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17 years, 2 months
Scala
by Michael Neale
Hey All. I have been looking into scala for sometime, and recently
started using it for a testing tool (kind of a replacement for the
"fit for rules" library).
I have been quite impressed with it, the tool integration (with
intelliJ) is outstanding, and it works nice with maven (even with
mixed java source).
Assuming this goes well, I am thinking of extending the usage of scala
to the server side components of bits of guvnor (obviously the client
is still GWT). Probably in a small way at first (I have found that
common annoying bits of code in java can be much clearer in scala -
examples to come !).
I was interested in what people think about this? Does it make it
harder for people to get into the code (I am not aiming to write the
densest scala, just use it when approriate)?
The main downsides I see are: Eclipse support - the plugin for eclipse
for scala is not great at the moment (netbeans or intelliJ would be
better), and general familiarity for people to read (although I
personally think it would take anyone who reads this list minutes to
learn enough to follow the simple things I would do).
Thoughts? Objections?
FAQ: Why scala? well its closer to java in intent then all other
popular JVM languages (ie its static) and compiles down similarly to
result in similar performance (better in some cases). I use "closures"
a lot (thanks to GWT that got be in the habit) but the inner class way
of doing it in java gets combersome.
--
Michael D Neale
home: www.michaelneale.net
blog: michaelneale.blogspot.com
17 years, 2 months
community skype meetings
by Mark Proctor
Does anyone here like the idea of community skype meetings? We already
have irc which is very open, but nothing is ever scheduled, we could
schedule a once a month (more if demand needs) skype meeting. What do
people think, and what would people like to discuss?
Mark
17 years, 2 months
Re: [rules-dev] LiteralRestriction NPE
by Michael Neale
Hi dave.
So that was found when running the verifier - but you chased it down
to double handling ?
If so, a bug report would be awesome as all the databtype permutations
are awesome.
Sent from my phone.
On 30/12/2008, at 12:34, "David Sinclair" <dsinclair(a)chariotsolutions.com
> wrote:
> Found a NullPointerException when using the verifier module.
> LiteralRestriction.setValue blows chunks, when the value is null. It
> sucks that Double.parseDouble doesn't behave the same as
> Integer.parseInt which handles nulls.
>
> java.lang.NullPointerException
> at sun.misc.FloatingDecimal.readJavaFormatString
> (FloatingDecimal.java:991)
> at java.lang.Double.parseDouble(Double.java:510)
> at org.drools.verifier.components.LiteralRestriction.setValue
> (LiteralRestriction.java:128)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:688)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:123)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:572)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:562)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:119)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:482)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:183)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:529)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:113)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:482)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:410)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:111)
> at org.drools.verifier.PackageDescrFlattener.flatten
> (PackageDescrFlattener.java:389)
> at
> org.drools.verifier.PackageDescrFlattener.addPackageDescrToData
> (PackageDescrFlattener.java:96)
> at org.drools.verifier.Verifier.addPackageDescr(Verifier.java:32)
> at
> com.sungard.cmdb.generator.RuleGenerator.createValidationPackage
> (RuleGenerator.java:370)
> at com.sungard.cmdb.generator.RuleGenerator.generateCode
> (RuleGenerator.java:273)
> at com.sungard.cmdb.generator.JarBasedCodeGenerator.main
> (JarBasedCodeGenerator.java:156)
> _______________________________________________
> rules-dev mailing list
> rules-dev(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-dev
17 years, 2 months
Creating DSLR
by Sarath Kumar Daruru
Hi,
I have small doubt in rules engine. I have downloaded the example and successfully ran those ones.
For generating the drl file I used .brl file, for this I have used guide editor.
Similarly is there any other way to generate the .dslr file using .dsl file?
My requirement is automatically create the DSLR file by using dsl file. Is it possible with drools IDE?
Ahead Together,
Sarath Kumar Daruru
Associate Technical Lead - (TEG) | BlueAlly (A Megasoft Division)
Megasoft Limited| 6-3-1192/2/1| Kundanbagh| Begumpet| Hyderabad-16|
Phone: +91 40 4033 0000 Extension 8175
Mobile: +91 994 999 3152
Email: sarathd(a)blueally.com
-----Original Message-----
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Sent: Thursday, January 01, 2009 10:30 PM
To: rules-dev(a)lists.jboss.org
Subject: rules-dev Digest, Vol 25, Issue 1
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Today's Topics:
1. Enumeration inconsistency in Guvnor (David Sinclair)
----------------------------------------------------------------------
Message: 1
Date: Wed, 31 Dec 2008 13:29:36 -0500
From: "David Sinclair" <dsinclair(a)chariotsolutions.com>
Subject: [rules-dev] Enumeration inconsistency in Guvnor
To: "Rules Dev List" <rules-dev(a)lists.jboss.org>
Message-ID:
<757cc9480812311029x5c7515f6r347ba152928e612c(a)mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"
When using the business guided editor for building a rule and choosing a
field for which an enumeration is defined such as
'Person.age' : ['1=one', '2=two', '3=three']
it will show the description, ie one, two, three. But when configured using
a DSL or in the web based decision table, they are shown as 1=one, 2=two,
3=three.
Was this done purposely, or is this an omission? I am using the trunk as of
a couple of days ago.
thanks
dave
17 years, 2 months
